The present invention relates to a hole closing plug, sometimes called an obturator, for closing an aperture in a barrier such as a metal door, water craft body panel, automobile body panel, double walled appliance wall and exterior wall of a fixed or mobile residence, and the like. The present invention has particular utility for closing an opening through a partition leading to an enclosed volume that is to be filled with insulating foam.
Hole closing plugs are used to tightly close apertures generally produced in barriers, partitions, dividers and walls that can be part of an overall enclosure and can be formed of a variety of materials including sheet steel. The hole closing plugs are typically formed of an injection molded thermoplastics material that are at least somewhat flexible and resilient. The hole closing plugs of the prior art typically have a central portion surrounded by a peripheral rim adapted to come into tight abutment against the periphery of the aperture sought to be closed. The hole closing plugs are typically retained in place by flanges or lugs that engage the periphery of the aperture. Examples are to be found in U.S. Pat. Nos. 3,739,936; 4,053,084; 4,037,754; and 6,296,136.
Some hole closing plugs, shown for example in U.S. Pat. Nos. 2,173,843; 3,904,071; and 4,915,252, include handles by which the plugs can be manipulated during insertion. Other hole closing plugs, shown for example in U.S. Pat. No. 4,640,434, are intended to be trimmed after insertion into the hole. While each of these structures have their own features and functions, there is still a need for a hole closing plug that can be stably pre-positioned adjacent to a hole and quickly moved into a hole closing position with a simple movement. There is also a need for a hole closing plug that can be manipulated with a knob or other protrusion that is removable subsequent to insertion of the closure into the opening. There is particularly a need for such a hole closing plug from which the handle can be removed quickly. There is also a particular need for such a hole closing plug that can be used, for example, to close a hole in a hollow wall or door of a structure, such as a refrigerator or other appliance, mobile home or recreational water craft, in which one desires to place insulation, particularly foaming insulation which is installed in a liquid form and then permitted to expand to fill the space within the hollow wall, preferably prior to any expansion of the foam so that the insulation is retained within the space rather than spilling out.